Carburetor



P. 8. TI CE CARBURETOR Aug. 20, 1929.

Original Filed Sept. 11, 1924 Hill Patented Aug. 20, 1929.

UNITED STATES PERCIVAL S. TICE, OF CHICAGO, ILLINOIS.

GARBURETOR.

Application filed September 11, 1924, Serial No. 737,017. Renewed December 14, 1928.

The purpose of this invention is to provide a carburetor or fuel mixture supplying device for internal combustion engines having means for obtaining a momentary enrichment of the fuel mixture for quick acceleration automatically upon throttle adjustment for acceleration, without maintenance of the excessive enrichment after the acceleration has been obtained. It consists in the ele ments and features of construction shown and described as indicated in the claims.

In the drawings:

Figure 1 is a top plan view of a carburetor embodying this invention, being a section at the line 1 1 on Figure 2.

Figure 2 is a section at the line 22 on Figure 1.

Figure 3 is a section at the line 33 on Figure 2.

Figure 4 is a detail section in the same plane as Figure 2 showing a portion of the construction in a modified form.

Figure 5 is a detail section at the line,

tension, 11, having free communication with the bowl 10, the air fuel mixture conduit, 12, communicating with the upper part of the level-governing chamber at an opening, 12, into the extension, 11, having a bridge at 13 in which the fuel nozzle, 14, is mounted, and a venturi, 15, constituting a flow-accelerating constriction in the fuel mixture intake to the engine the cavity of the level governing chamber is continuous throughout the unitary casting which comprises the float bowl proper, d, a laterally situated portion al and a neck, dflwhich connects the part D and al said continuous cavity being closed at the left hand side by a cap, 2 1, as hereinafter more particularly mentioned. The fuel from the level-governing chamber is led to the nozzle by way of the extension, 11, and a duct, 13., in the bridge, 18, a tubular element, 16, being provided telescoping in the duct, 13, the duct and said telescoping tubular element being provided with registering apertures, 17 and 18, for metering, l. e., restricting according to the extent of registration of said apertures-the access of fuel to the nozzle.

In this construction the air and fuel passages and the constriction of the intake to the engine afforded by the venturi, 15, are so related that in practice it is possible to secure maximum economy of fuel and at the same time obtain proper mixture proportions for developing maximum power at the condit1on of fully open throttle. But it is found with the proportions and relations for glvlng these results, in the absence of some additional expedient, the acceleration upon increase of throttle opening is weak at all moderate degrees of opening of the throttle, and is satisfactory only when the opening approximates maximum. The present inventlon is designed to correct this defect, which it is thought may be done by sacrific- 1ng somewhat of the fuel economy at and during the momentary or short periods of acceleration only, and without loss in respect to economy of fuel throughout all periods of ponstant speed, whether the speed be high or Quick acceleration is obtained by the following expedient which constitutes the chief characteristic of the present invention;

In the level-governing chamber below the governed liquid level, and conveniently in the extension, 11, there is located an expansible and contractible element, 20, which is desirable of the character of a sylphon, i. e. a hollow completely enclosed metal shell having its longitudinal walls corrugated or equivalently formed so as to render the shell expansible and eontractible longitudinally, and the drawing may be understood as representing either such a sylphon, or a plurality of single cells accumulated co-axially one upon another. This expansible and contractible device, whether a unitary sylphon or a plurality of cells as Figure 2 may be understood, is seated in a boss, 21, formed projecting into the extension, 11, from the air intake conduit, 12, said boss being bored to position and accommodate the sylphon or group of cells, with the inner end or head of the sylphon or group stopped at the bottom of the bore and the outer head, 22, exposed to the pressure of the liquid in the level-governing chamber, said outer head being desirably guided in the outer end portion of the bore and having a stem, 23, beduring which the pressure due to change tween which and the cap, 24, which closes of throttle opening is occurring.

the level-governing chamber at that side, a In figure 4 there is shown a modificat on spring, 25, is interposed and reacts to thrust of the structure in respect to the operating the head, 22,, inward and compress or conconnections between the expansible and contract the sylphon or cells constituting the extractible element, 20, and the telescoping pillnsible contractible devlcei tubular member, 16, for ad ustment at Wlll 26, fulcrumed at one end on a stud, 27, set f th t n i n of th rin 25, nd f th into the bOSS ngag at the pp end fulcrum of the lever, 26. In this modifica- With the telesc pi g tubular member, y tion the cap. 24, has an interiorily and exteri- WlllCh the tLCCQSS 0f fuel to the nozzle is (3011- rfly threaded h n w boss 24 ac trolled; and intermediate its ends the lever commodates a screw th d d Stem 30 d a is pivotally connected with the stem, 23, of the outer head of the expansible and contractible device. I

The operation of the structure descrlbed is as follows:

With the engine not running the expansible and contractible device, 20, occupies the least volume being compressed by the spring,

25; and the plunger or piston head, 22, is in its farthest inthrust position, and the liquid capacity of the duct, 13, is at minimum. Assuming the engine to be started and operated under small load, as idling, the small opening of the throttle, C, to'secure this condition, causes a much reduced pressure to exist throughout the air and fuel mixture conduit leading to the engine and in the float chamber above the liquid therein in which liquid the expansible and contractible device, 20, is submerged. Such reduced pressure causes or permits the sylphon. or cells, 20, to expand by virtue of the air at atmospheric pressure therein, and the head, 22, is thereby thrust out, and through the lever, 26, causes the telescoping element, 16, to be withdrawn from the duct 13, thus increasing the liquid capacity of said duct. If now the throttle is opened a small amount, the pressure on the liquid in the level-governing chamber is increased and the expansible and contractible device, 20, is compressed or contracted an amount suflicient to establish equilibrium with the spring, 25, thus moving the head, 22, and causing it to thrust in the element, 16, and reduce the liquid capacity passage, 13*. Since there is a control of the mean rate of flow of fuel at the registering metering passages, 17 and 18, and since the nozzle fuel passages are relatively very free, this movement of. the head, 22, causes the displacement of fuel from the passage, 13*, which displaced fuel largely issues from the nozzle, 14, and constitutes an addition to the uantity 'of fuel normally discharged thererom, there'by momentarily enriching the mixture as desired and causing prompt acceleration. So long as the pressure in the level-governing chamber is not changing, the head, 22, of the expansible and contractible device is stationary, and this device, therefore, has no effect upon the amount of fuel drawn through the nozzle after the instant stuffing box, 31, about that stem, the stem being directed against a disk, 32, yvith which the spring, 25, is provided for seating the end of the screw. Said screw being screwed in more or less through the boss, 24*, tensions the spring more or less.

For providing means for shifting the fulcrum of the lever, 26, the cap, 24, has an ex teriorily and interiorily threaded hollow boss, 35, through which is screwed a stem, 36. and onto which is screwed a stufiing box, 37. The stem, 35, has a spherical terminal seen at 38 which constitutes its sliding pivotal engagement with the lever. 26, and constitutes an adjustable fulcrum for that lever. A handle, 39, on the outer end of the stem, 35, serves for screwing the stem in and out through the boss for shifting the fulcrum of the lever.

I claim:

1. In a carburetor in combination with a level-governing chamber, an air and fuel mixture passage having a flow-accelerating construction, a 'fuel discharge nozzle discharging into the constricted region of the fuel mixture passage and a cavity comprising a passage for the fuel from the level governing chamber to said nozzle: the levelgoverning chamber having communication above the governed liquid level with the air and fuel mixture passage at a point other than in the region of flow acceleration: means for altering the liquid capacity of the cavity which comprises the passage from the level-governing chamber to the nozzle; an expansible and contractible device submerged in the liquid contents of a levelgoverning chamber; an operating connection from said expansible and contractible device to said liquid-capacity-altering means; whereby change in the pressure on the liquid in the level-governing chamber altering said liquid capacity tends to drive the liquid from said passage to the nozzle.

2. In the construction defined in claim 1, foregoing, the communication from the level-governing chamber to the nozzle comprising a duct and a tubular element telescoping with said duct, the duct and telescoping element having registrable metering ports positioned for varying the extent oftheir registration by the telescoping movement of said tubular element and the liquidcapacity-altering means being located between said metering orts and the nozzle.

3. In the construction defined in claim 1, foregoing, an expansible and contractible element com rising one or more completely enclosed hol ow flexible walled shells normally contracted and occupied with air at atmospheric pressure, whereby said shell or shells tend to expand upon the pressure u on the liquid in t e level-governing cham er becoming sub-atmospheric.

4. In the construction defined in claim 1, foregoing, the carburetor havin an anterior throttle, and means operative y connected with the expansible and contractible device to hold the latter contracted or com ressed and adapted to yield to pressure ten ing to expa d said devlce.

5. la the construction defined in claim 1, foregoing, the carburetor having an anterior throttle, and spring means operatively connected with the expansible and contractible device for yieldingly contracting or compressing it, said device being a closed shell normally occupied by air at atmospheric tens1on.

6. In the construction defined in claim 1, foregoing, the carburetor having an anterior throttle, and spring means operatively connected with the expansible and contractible device for yieldingly contracting it, said device being a closed shell normally occupied by air at atmospheric tension, and exterior means for varying at will the tension of said spring means.

7. In the construction defined in claim 1,

foregoing, the operating connection from the expansible and contractible device to the fuel-capacity-var ing means comprising a lever having a s iftable fulcrum and exteriorly operative means for shifting the fulcrum at will to change the range of variability of the fuel capacit of the cavity cpmprising the passage lea ing to the nozz e.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 8th day of Sept, 1924.

PERGIVAL S. TICE. 

